/*
 * Copyright ${inceptionYear} - ${year} ${owner}
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package jetbrains.exodus.crypto

import kotlin.experimental.xor

class TrivialStreamCipher : StreamCipher {

    private lateinit var key: ByteArray
    private var iv: Int = 0

    override fun init(key: ByteArray, iv: Long) {
        this.key = key
        this.iv = iv.toInt() xor (iv shr 32).toInt()
    }

    override fun crypt(b: Byte): Byte {
        return b xor key[(iv++ and 0x7fffffff).rem(key.size)]
    }
}
